Using Credit Card Balance Transfer as Down Payment

[Vivek Jalahalli]

If I get balance transfer from 3 cards totally $30K and then add up my personal savings of  $30K , totaling $60K to make a 20% downpayment for $300K rental investment.

Does banks have problem providing mortgage loans ? if they see me taking 30K on balance transfer 

Credit report will obviously show my balance transfer amount. Banks might ask what is this for?

Is it GOOD or BAD on my credit ?

any advice on getting cash for down payments ? 

Balance transfer that I'm getting from 3 cards are as 0% for next 18months with 3% service fee initially.